Mr Ong said in a Facebook post on Monday night (Apr 22) that the penalties meted out by NUS were "manifestly inadequate in the recent sexual misconduct case".

He wrote that he spoke to the NUS President and Board Chairman on Saturday (Apr 19) to convey his concerns.

"From here on, for offences that affect the safety of students on campus, we have to take a tough stand, and send a strong signal to everyone," he added.

"Two strikes and you are out cannot be the standard application.

"NUS has to make its campus safe for all students, especially female students."

He said NUS will review its discipline and sentencing framework "swiftly and decisively".

"I am confident NUS' review will result in a more robust process and stricter framework," he said.

"The NUS Board and President are seized with this matter, and are determined to put a stop to such unacceptable behaviour on campus."

Mr Ong's comments come after 23-year-old NUS undergraduate Monica Baey took to Instagram to share how she was recorded by a fellow student while she was showering in her hostel bathroom at Eusoff Hall last November.

After he was slapped with a 12-month conditional warning, she wrote she wanted "real consequences for perpetrators that commit such acts".